A pre-evaporative flame intake air preheating device, diesel engine and intake air preheating method

Abstract

This invention discloses a pre-evaporation type flame intake preheating device, a diesel engine, and an intake preheating method, belonging to the field of diesel engine technology. It includes an electronically controlled fuel injector, an electric heating evaporator, a flame stabilizer, and an electric heating element. The flame stabilizer has a chamber with one open end and the other closed end, and through holes and two symmetrical wing plates are provided on the chamber wall. The fuel injection outlet of the electronically controlled fuel injector is connected to one end of the electric heating evaporator, and the other end of the electric heating evaporator is connected to the inlet of the flame stabilizer. The electronically controlled fuel injector can inject fuel into the electric heating evaporator and heat it into gaseous fuel. After entering the chamber, the gaseous fuel is ejected from the through hole. The gaseous fuel ejected from the through hole can be driven by the incoming air flow in the diesel engine intake manifold and flows along the outer wall of the wing plate towards the tail end of the wing plate, forming a vortex recirculation zone at the tail end of the wing plate. The electric heating element is located in the vortex recirculation zone. This intake preheating device increases the intake air temperature of the diesel engine, improving the cold start performance of the diesel engine.

Description

Technical Field

[0001] This invention belongs to the field of diesel engine technology, specifically relating to a pre-evaporation type flame intake preheating device, a diesel engine, and an intake preheating method. Background Technology

[0002] Preheating the intake air of a diesel engine, raising the atmospheric temperature before it enters the engine, effectively increases the cylinder compression final temperature, preventing misfires and is a crucial means of addressing the poor cold-start performance of diesel engines in high-altitude environments. Since the exhaust gas turbocharger is inactive during the cold start phase, only the fresh air heated by the intake preheating device enters the diesel engine cylinder directly; therefore, the intake preheating device is essential for cold starts. Unlike electrically heated intake preheating devices, flame intake preheating utilizes the combustion of fuel and air within the diesel engine's intake manifold to raise the intake air temperature. Previous diesel engine flame intake preheating devices, such as those published in Chinese patent applications CN2147362Y, CN 116398333 A, and CN 112855403 A, all supply diesel fuel to a separate high-temperature wall. Under the heating effect of the high-temperature wall, the liquid fuel evaporates and vaporizes, mixes with the incoming air, and is then ignited by the high-temperature wall to form a stable flame. Because there is only one heating element, the vaporization, mixing, ignition, and combustion processes of liquid fuel in the above patent applications are highly coupled, which presents the following problems: 1) In order to ensure stable ignition, the surface temperature of the heating element generally needs to be higher than 800°C, which increases the design difficulty of the heating element; 2) When liquid fuel flows through or is sprayed onto a high-temperature wall surface above 800°C, its vaporization efficiency is greatly reduced due to the Leidenfrost effect, which is not conducive to the formation of gaseous fuel; 3) When fuel comes into contact with a high-temperature wall surface above 800°C, coking is very likely to occur, leading to oil circuit blockage and heating element ablation; 4) The vaporization, mixing, ignition, and combustion processes of fuel occur simultaneously and are highly coupled, making it difficult to achieve the optimal design of structural performance.

[0003] Therefore, in order to improve the cold start performance of diesel engines in high-altitude and low-temperature environments, a new type of pre-evaporation flame intake preheating device is needed. Summary of the Invention

[0004] In view of this, the present invention provides a pre-evaporation flame intake preheating device, a diesel engine, and an intake preheating method. The pre-evaporation flame intake preheating device improves the cold start performance of the diesel engine in high-altitude and low-temperature environments and solves the technical problem of traditional diesel engine flame intake preheating devices igniting the fuel-air mixture through a high-temperature wall surface to form a stable flame.

[0005] The present invention adopts the following technical solution:

[0006] A pre-evaporation type flame air intake preheating device includes an electronically controlled fuel injector, an electric heating evaporator, a flame stabilizer, and an electric heating element;

[0007] The flame stabilizer is provided with a chamber that is open at one end and closed at the other end, and has through holes and two symmetrical wing plates on the wall of the chamber.

[0008] The fuel injection outlet of the electronic fuel injector is connected to one end of the electric heating evaporator tube, and the other end of the electric heating evaporator tube is connected to the inlet of the flame stabilizer.

[0009] The electronically controlled fuel injector can inject fuel into the electric heating evaporator tube and heat it into gaseous fuel. After the gaseous fuel enters the chamber, it is ejected from the through hole. The gaseous fuel ejected from the through hole can flow along the outer wall of the wing plate towards the tail end of the wing plate under the push of the incoming air in the diesel engine intake pipe, and form a vortex backflow zone at the tail end of the wing plate.

[0010] The electric heating element is disposed in the vortex recirculation zone.

[0011] Furthermore, the electric heating evaporator is a ceramic electric heating evaporator;

[0012] The electric heating element is a silicon nitride heating rod.

[0013] Furthermore, the diameter of the through hole is 1 to 3 mm.

[0014] Furthermore, it also includes an electric fuel pump, a fuel inlet pipe, an electronic fuel injector inlet flange, a fuel injector outlet base, an electric heating evaporator mounting base, and a preheating device mounting base;

[0015] One end of the fuel inlet pipe is connected to the electric fuel pump, and the other end is connected to the fuel inlet of the electronic fuel injector through the fuel inlet flange of the electronic fuel injector. The fuel inlet pipe is used to supply fuel to the electronic fuel injector, and the electric fuel pump is used to increase the fuel supply pressure.

[0016] The outlet of the electronically controlled fuel injector is connected to the electric heating evaporator tube through the fuel outlet base of the electronically controlled fuel injector.

[0017] The electric heating evaporator tube is connected to the flame stabilizer via the electric heating evaporator tube mounting base;

[0018] Both the electric heating element and the flame stabilizer are mounted on the preheating device mounting base.

[0019] The present invention also provides a diesel engine, wherein the diesel engine is provided with the above-mentioned pre-evaporation type flame intake preheating device, and the flame stabilizer and the electric heating element are both located inside the intake pipe of the diesel engine.

[0020] Furthermore, the pipe wall of the flame stabilizer with the through hole is located on the side of the air inlet pipe facing the incoming flow direction.

[0021] Furthermore, the electric heating evaporator is installed in a non-vertical state.

[0022] The present invention also provides a method for preheating the intake air of a diesel engine, wherein the temperature of the electric heating evaporator is controlled at 180°C to 250°C using the aforementioned diesel engine.

[0023] Furthermore, the temperature of the electric heating element is controlled above 1000℃.

[0024] Furthermore, the injection frequency of the electronically controlled fuel injector is controlled to be 1-40 Hz, and the duration is 0.5-5 ms.

[0025] Beneficial effects:

[0026] 1. The flame stabilizer is equipped with a chamber that is open at one end and closed at the other end. The chamber wall has through holes and two symmetrical wing plates. The fuel injection outlet of the electronic fuel injector is connected to one end of the electric heating evaporator tube, and the other end of the electric heating evaporator tube is connected to the inlet of the flame stabilizer. The electronic fuel injector can inject fuel into the electric heating evaporator tube to heat it into gaseous fuel. After the gaseous fuel enters the chamber, it is sprayed out from the through hole. The gaseous fuel sprayed out from the through hole can be pushed by the incoming air flow in the diesel engine intake manifold and flow along the outer wall of the wing plate towards the tail end of the wing plate, forming a vortex recirculation zone at the tail end of the wing plate. The electric heating element is located in the vortex recirculation zone.

[0027] Thus, by using an electronically controlled fuel injector to control the fuel supply rate, and employing an electric heating evaporator to pre-evaporate the fuel and form gaseous fuel before injecting it into the flame stabilizer, the gaseous fuel inside the flame stabilizer can be ejected from the through-hole. Driven by the incoming airflow in the diesel engine's intake manifold, the gaseous fuel flows along the outer wall of the winglet towards the tail end of the winglet, forming a vortex recirculation zone at the tail end. The electric heating element in this vortex recirculation zone achieves stable ignition and combustion of the gaseous fuel-air mixture, ultimately increasing the diesel engine's intake air temperature and improving its cold-start performance. This solves the technical problem of traditional diesel engine flame intake preheating devices that rely on high-temperature walls to ignite the fuel-air mixture and form a stable flame. Furthermore, utilizing the winglet to create the vortex recirculation zone results in a simple and compact structure.

[0028] 2. The electric heating evaporator is a ceramic electric heating evaporator, which heats evenly. As the temperature rises, the power consumption will decrease, achieving an energy-saving effect. The electric heating element is a silicon nitride heating rod, which has high thermal efficiency. Moreover, the silicon nitride heating rod itself does not produce harmful gases or emit waste that pollutes the environment when heating.

[0029] 3. The diameter of the through hole is 1 to 3 mm, which allows gaseous fuel to be stably sprayed out from the through hole of the flame stabilizer.

[0030] 4. The electric heating evaporator tube is installed in a non-vertical state, which can prevent liquid fuel from entering the flame stabilizer chamber directly without contacting the wall of the electric heating evaporator tube, and ensure that the liquid fuel is fully heated into gaseous fuel before entering the flame stabilizer chamber.

[0031] 5. The temperature of the electric heating evaporator is controlled at 180℃~250℃ to ensure that the liquid fuel evaporates without causing the fuel to coke.

[0032] 6. The temperature of the electric heating element is controlled above 1000℃, which can quickly ignite the mixture of fuel and air to form a flame. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a pre-evaporation type flame air intake preheating device provided by the present invention;

[0034] Figure 2 A cross-sectional schematic diagram of a pre-evaporation type flame air intake preheating device provided by the present invention;

[0035] Figure 3 A schematic diagram illustrating the principle of forming a vortex recirculation zone in a pre-evaporation type flame air intake preheating device provided by the present invention;

[0036] Among them, 1-oil inlet pipe, 2-oil inlet flange of electronic fuel injector, 3-wire terminal of electronic fuel injector, 4-electronic fuel injector, 5-oil outlet base of electronic fuel injector, 6-electric heating evaporator tube, 7-wire terminal of evaporator tube, 8-mounting base of electric heating evaporator tube, 9-flame stabilizer, 10-through hole, 11-electric heating element, 12-wire terminal of electric heating rod, 13-mounting base of preheating device, 14-air inlet pipe, 15-chamber, 16-vortex reflux zone, 17-wing plate. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] Example 1:

[0039] Reference Figures 1-3 A pre-evaporation type flame intake preheating device includes an electronically controlled fuel injector 4, an electric heating evaporator 6, a flame stabilizer 9, and an electric heating element 11, wherein:

[0040] The flame stabilizer 9 is provided with a chamber 15 that is open at one end and closed at the other end, and through holes and two symmetrical wing plates 17 are provided on the wall of the chamber 15; the fuel injection outlet of the electronic fuel injector 4 is connected to one end of the electric heating evaporator tube 6, and the other end of the electric heating evaporator tube 6 is connected to the inlet of the flame stabilizer 9; the electronic fuel injector 4 can inject fuel into the electric heating evaporator tube 6 to heat it into gaseous fuel. After the gaseous fuel enters the chamber 15, it is sprayed out from the through hole 10. The gaseous fuel sprayed out from the through hole 10 can be pushed by the incoming air in the diesel engine intake pipe 14 to flow along the outer wall of the wing plate 17 towards the tail end of the wing plate 17, and form a vortex recirculation zone 16 at the tail end of the wing plate 17; the electric heating element 11 is provided in the vortex recirculation zone 16.

[0041] Thus, the fuel supply rate is controlled by an electronically controlled fuel injector 4, and the fuel is pre-evaporated and formed into gaseous fuel by an electric heating evaporator tube 6 before being injected into the flame stabilizer 9. The gaseous fuel entering the flame stabilizer 9 can be ejected from the through hole 10. The gaseous fuel ejected from the through hole 10 can be pushed by the incoming air flow in the diesel engine intake manifold 14 and flow along the outer wall of the wing 17 towards the tail end of the wing 17, forming a vortex recirculation zone 16 at the tail end of the wing 17. The electric heating element 11 of the vortex recirculation zone 16 is used to achieve stable ignition and combustion of the gaseous fuel-air mixture, ultimately increasing the intake air temperature of the diesel engine and improving the cold start performance of the diesel engine. This solves the technical problem of traditional diesel engine flame intake preheating devices that ignite the fuel mixture through a high-temperature wall surface to form a stable flame. In addition, the vortex recirculation zone 16 formed by the wing 17 has a simple and compact structure.

[0042] In this embodiment, the electric heating evaporator 6 is a ceramic electric heating evaporator, which provides uniform heating. As the temperature rises, the power consumption decreases, achieving energy-saving effects. The electric heating element 11 is a silicon nitride heating rod, which has high thermal efficiency and does not produce harmful gases or emit waste that pollutes the environment during heating. Moreover, in this embodiment, the diameter of the through hole 10 is 1-3 mm, which allows gaseous fuel oil to be stably ejected from the through hole 10 of the flame stabilizer 9.

[0043] Specifically, in this embodiment, the pre-evaporation type flame intake preheating device provided in this embodiment further includes an electric fuel pump (not shown in the figure), a fuel inlet pipe 1, an electronic fuel injector inlet flange 2, an electronic fuel injector outlet base 5, an electric heating evaporator mounting base 8, and a preheating device mounting base 13. One end of the fuel inlet pipe 1 is connected to the electric fuel pump, and the other end is connected to the inlet of the electronic fuel injector 4 via the electronic fuel injector inlet flange 2. The fuel inlet pipe 1 is used to supply fuel to the electronic fuel injector 4, and the electric fuel pump is used to increase the fuel supply pressure. The outlet of the electronic fuel injector 4 is connected to the electric heating evaporator 6 via the injector outlet base 5. The electric heating evaporator 6 is connected to the flame stabilizer 9 via the electric heating evaporator mounting base 8. The electric heating element 11 and the flame stabilizer 9 are both mounted on the preheating device mounting base 13.

[0044] More specifically, the electronic fuel injector 4 is equipped with an electronic fuel injector terminal 3 for connection to the electronic control device; the electric heating evaporator tube 6 is equipped with an evaporator tube terminal 7 for connection to the electronic control device; and the ceramic electric heating rod is equipped with an electric heating rod terminal 12 for connection to the electronic control device. Furthermore, referring to… Figure 3 In this embodiment, the cross-sectional structure of the chamber 15 is an isosceles right-angled triangle, and the through hole 10 and the two wing plates 17 are symmetrically arranged on the right-angled sides. Setting the chamber 15 into a triangular structure makes the flame stabilizer 9 easier to manufacture. In this embodiment, the flame stabilizer 9 is formed by flat plate welding, which is simple in structure. In addition, in this embodiment, the evaporator tube terminal 7 and the electric heating evaporator tube mounting base 8 are both made of ceramic material.

[0045] The pre-evaporation flame intake preheating device provided in this embodiment pre-evaporates liquid fuel before igniting it, thus decoupling fuel vaporization, air mixing, and ignition. This effectively avoids the problems of low fuel vaporization efficiency, coking and blockage, heating element erosion, and design optimization difficulties that exist in existing flame intake preheating devices, thereby improving the cold start performance of diesel engines.

[0046] Example 2:

[0047] Based on the above embodiment one, this embodiment provides a diesel engine equipped with the pre-evaporation type flame intake preheating device of embodiment one, and the flame stabilizer 9 and the electric heating element 11 are both located inside the intake pipe 1 of the diesel engine. Specifically, the preheating device mounting base 13 is fixed to the wall of the engine intake pipe 14 with screws.

[0048] Reference Figure 3 The flame stabilizer 9 has a through hole 10 on its pipe wall located on the side of the diesel engine intake pipe 1 in the direction of incoming flow. Moreover, the electric heating evaporator 6 is installed in a non-vertical state, which can prevent liquid fuel from entering the chamber of the flame stabilizer 9 directly without contacting the wall of the electric heating evaporator 6. This ensures that the liquid fuel is fully heated into gaseous fuel before entering the chamber of the flame stabilizer 9.

[0049] Reference Figure 2Liquid fuel enters the electronically controlled fuel injector 4 through inlet 1 and inlet flange 2. After receiving a control signal via terminal 3, terminal 4 injects the liquid fuel into the inner cavity of injector outlet base 5 at a specific injection frequency and duration. Internal flow channels in injector outlet base 5 connect its inner cavity to the electric heating evaporator tube 6. When power is supplied to terminal 7, the internal wall temperature of electric heating evaporator tube 6 rises, vaporizing the incoming liquid fuel and forming gaseous fuel, which flows out from outlet 6 to electric heating evaporator tube mounting base 8. Internal flow channels in electric heating evaporator tube mounting base 8 and preheating device mounting base 13 connect outlet 8 to chamber 15, through which fuel flows into chamber 15 of flame stabilizer 9, and then exits through through hole 10 into intake manifold 14 of diesel engine. (Refer to...) Figure 3 Gaseous fuel is injected into the intake pipe 14 through the through-hole 10 and mixes with part of the incoming air to form a combustible mixture. Driven by the incoming air, the combustible mixture flows rearward along the outer walls of the flame stabilizer's side vanes 17, subsequently forming a vortex recirculation zone 16 near the tail end of the flame stabilizer vanes 17. Within the vortex recirculation zone 16, the combustible mixture flow rate decreases and the residence time increases, making the combustible mixture easier to ignite and more stable in combustion. Electric heating elements are arranged near the vortex recirculation zone 16 to ignite the combustible mixture and form a stable flame. Subsequently, the high-temperature exhaust gas after combustion mixes with the incoming cold air, ultimately increasing the temperature of the incoming air.

[0050] Example 3:

[0051] Based on the above-described embodiment two, this embodiment provides a method for preheating the intake air of a diesel engine. This method controls the temperature of the electric heating evaporator 6 to 180℃~250℃, ensuring that the liquid fuel evaporates without causing coking. The temperature of the electric heating element 11 is controlled above 1000℃, enabling rapid ignition of the fuel-air mixture to form a flame. Furthermore, the injection frequency and duration of the electronically controlled fuel injector 4 can be adjusted according to the incoming airflow rate. Generally, the injection frequency of the electronically controlled fuel injector 4 can be 1~40Hz, and the duration can be 0.5-5ms.

[0052] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pre-evaporation type flame air inlet preheating device, characterized in that, This includes electronic fuel injectors, electric heating evaporator tubes, flame stabilizers, and electric heating elements; The flame stabilizer is provided with a chamber that is open at one end and closed at the other end, and has through holes and two symmetrical wing plates on the wall of the chamber. The fuel injection outlet of the electronic fuel injector is connected to one end of the electric heating evaporator tube, and the other end of the electric heating evaporator tube is connected to the inlet of the flame stabilizer. The electronic fuel injector can inject fuel into the electric heating evaporator tube and heat it into gaseous fuel. After the gaseous fuel enters the chamber, it is ejected from the through hole. The gaseous fuel ejected from the through hole can flow along the outer wall of the wing towards the tail end of the wing under the push of the incoming air in the diesel engine intake manifold, and form a vortex backflow zone at the tail end of the wing. The electric heating element is disposed in the vortex recirculation zone.

2. The pre-evaporation type flame air inlet preheating device according to claim 1, characterized in that, The electric heating evaporator is a ceramic electric heating evaporator; The electric heating element is a silicon nitride heating rod.

3. A pre-evaporation type flame air inlet preheating device according to claim 1 or 2, characterized in that, The diameter of the through hole is 1 to 3 mm.

4. The pre-evaporation type flame air inlet preheating device according to claim 3, characterized in that, It also includes an electric fuel pump, fuel inlet pipe, electronic fuel injector inlet flange, fuel injector outlet base, electric heating evaporator mounting base, and preheating device mounting base; One end of the fuel inlet pipe is connected to the electric fuel pump, and the other end is connected to the fuel inlet of the electronic fuel injector through the fuel inlet flange of the electronic fuel injector. The fuel inlet pipe is used to supply fuel to the electronic fuel injector, and the electric fuel pump is used to increase the fuel supply pressure. The outlet of the electronically controlled fuel injector is connected to the electric heating evaporator tube through the fuel outlet base of the electronically controlled fuel injector. The electric heating evaporator tube is connected to the flame stabilizer via the electric heating evaporator tube mounting base; Both the electric heating element and the flame stabilizer are mounted on the preheating device mounting base.

5. A diesel engine, characterized in that, The diesel engine is equipped with a pre-evaporation type flame intake preheating device as described in any one of claims 1 to 4, and the flame stabilizer and the electric heating element are both located inside the intake pipe of the diesel engine.

6. A diesel engine according to claim 5, characterized in that, The flame stabilizer with the through hole is located on the side of the inlet pipe in the direction of incoming flow.

7. A diesel engine according to claim 5 or 6, characterized in that, The electric heating evaporator tube is installed in a non-vertical state.

8. A method for preheating the intake air of a diesel engine, characterized in that, Using a diesel engine according to claim 6 or 7, the temperature of the electric heating evaporator is controlled to be 180°C to 250°C.

9. The intake air preheating method for a diesel engine according to claim 8, characterized in that, The temperature of the electric heating element is controlled above 1000℃.

10. A method for preheating the intake air of a diesel engine according to claim 8 or 9, characterized in that, The injection frequency of the electronically controlled fuel injector is controlled at 1-40 Hz, and the duration is 0.5-5 ms.

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